fan PWM frequency
Hi,
I have these fans for print cooling: XYJ24B3010H from XINYUJIE electronics, but they refuse to turn on any other setting than 100% (M106 S255).
Other type of fans on the same connection can be modulated. The board output voltage is OK, for example M106 S128 gives 13V and M106 S255 gives 24V.
In the configuration.h file setting PDM instead of PWM reduces fan power, but still only works at 100%.
The fan supplier does not react to my request for info.
Changing to another type of fan is not preferred, so I'm looking for a way to control the PWM speed in Repetier. Maybe changing the frequency could help.
Comments
take care on polarity!
had same problem with some small fans.
building a kind of step down converter.
from my experience problem appears mostly on brushless fans, depending on their internal electronics.
they cannot handle pwm on small pulsewidth.
And as repetier already mentioned, cheap fans work best
to get this running in a smooth way you´ll need pwm frequency in high kHz Range.
that´s not possible on AVR as far as i know.
(if Fans are started via Kickstart they keep moving caused by mass of propeller what´s totally different to your pump problem).
i did a couple of tests with external pwm controllers and "problematic" fans so result for a smooth running
i needed 20Khz ( i used TLC59711 controller from Adafruit ).
May be that could work for your pump also, i don´t know.
best solution from my point of view would be a pwm-controlled DC-DC converter.
any results?